Tankers loaded with combustible oil are not the first threat coming down the tracks along Glacier National Park. Grain spills that left corn fermenting in the sun once were so great a problem that grizzly bears drawn to the meal were basically run over and killed.

"Historically speaking with regards to the railroad, there have been incidents that have clearly impacted park resources," Glacier Superintendent Jeff Mow says. "Primarily they’ve been things like grain spills from cars that leaked grain. impacting bears that would then get run over by trains. Essentially, the grain would ferment in the sun, the bears would eat this fermented grain. As I understand it, they would literally lay down on the tracks and get run over by trains."

At the height of the problem back in the '90s, at least nine grizzlies, a threatened species, were killed, including five sows. At the time a story in the Los Angeles Times noted that a series of winter derailments dumped 10,000 tons of corn on the tracks that bears coming out of hibernation were drawn to.

Coming out of hibernation hungry in the spring of 1990, they soon discovered the fermenting corn caches. By fall, two dozen bears were hanging around the tracks. Six were killed by passing trains that year and the next.

The National Wildlife Federation and the Great Bear Foundation filed suit in federal court in May, 1991, contending that the railroad was illegally killing a federally protected species. The suit demanded a better cleanup.

Railroad lawyers argued that Burlington Northern was doing everything it could to clean up the area. The judge initially agreed. Then videotape shot by a local photographer came to light in 1992, showing that bears were still flocking to the spill area and digging up corn.